DE1224871B - Process for the production of spinning solutions from beta-polyamides - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

DOIf

German class: 29 b -3/60

Number: 1224 871

File number: F 34073 IV c / 29 b

Filing date: June 2, 1961

Opening day: September 15, 1966

The processing of the known polyamides into fibers or threads is either after melting or possible after the wet spinning process. It is known to use polyamides in alcoholic solutions inorganic salts such as calcium chloride, calcium nitrate, magnesium chloride and magnesium nitrate to solve; however, these solutions are very unsuitable for making durable spinning solutions.

It was also shown that a poly-ß-lactam, such as poly - /? - methyl-j8-butyrolactam, can be found in these Solvents either does not dissolve at all or that the initially formed polymer solutions, For example, in methanolic calcium chloride solutions, are very unstable, so that after a rapid increase in viscosity occurs again after a short time, coagulation occurs.

The subject of the invention are spinning solutions, the polyamides and rhodanides dissolved in alcoholic Solutions included. The spinning solutions according to the invention are characterized in that they are as Polyamides polymer jo-methyl-ß-butyrolactams or their copolymers, containing as rhodanide, calcium rhodanide and that in the spinning solutions the weight ratio of polymeric / 3-methyl / S-butyrolactam to calcium rhodanide 1: 1.3 to 1: 1.8 and that the calcium rhodanide concentration 20 to 28%.

It was very surprising that alcoholic solutions of calcium rhodanide poly- / S-lactams in the cold easily dissolve, since this salt is under the same conditions for polyamides downright as Has proven precipitant (see German Patent 737 950, p. 2).

It is noteworthy that alcoholic solutions of rhodanides of sodium, ammonium and the cadmium do not dissolve poly-jö-lactame under the same conditions; this also applies to alcoholic Solutions of potassium rhodanide, which is known from patent specification 1776 of the Office for Invention and patent systems in the Soviet zone of occupation in Germany.

Also used as a solvent for polyamides with more Structures between the CO-NH groups, such as polycaprolactam or polyhexamethylene adipamide, known alcoholic solutions of the chlorides or nitrates of calcium or magnesium, in particular of calcium chloride, are not suitable for the production of stable spinning solutions of the polymeric / 3-lactams, not even if the calcium chloride is used in an amount twice the equivalent represents the amount of calcium rhodanide used in the process according to the invention.

Process for the production of spinning solutions of /? - polyamides

Applicant:

Farbwerke Hoechst Aktiengesellschaft

formerly Master Lucius & Brüning, Frankfurt / M.

Named as inventor:

Dr. Hans Hoyer, Kelkheim (Taunus);

Dipl.-Chem. Horst Behrenbruch,

Frankfurt / M.-Unterliederbach;

Dr. Karl Börner, Bobingen

If you increase the ratio of poly - /? - lactam to Calcium rhodanide in favor of the salt, so one obtains solutions that are spinning because of the too high Behave much more unfavorably with the salt content. If you keep the weight ratio Poly - /? - lactam to calcium rhodanide in the limits 1: 1.3 to 1: 1.8 the approach with more alcohol, d. H.

diluted below 20 ° / ₀ ig that manufactures, one solutions, the filter is obtained only with difficulty. If one wanted to spin such solutions anyway, they would have to be centrifuged for a long time before filtration.

In order to obtain easily filterable solutions, it is advisable to initially concentrate the solutions in a slightly more concentrated manner and then to dilute them up to the spinning concentration. The one among these The solution produced under these conditions can be filtered easily and is also stable for a sufficiently long time. One can also use calcium rhodanide, which contains water of crystallization, but the amount of water should be 6.5 mol not be exceeded. If anhydrous calcium rhodanide is used, the alcohols in which the rhodanide is dissolved, the 6.5 mol corresponding amount of water in whole or in part be admitted.

Does the calcium rhodanide used contain crystal water or is it given for technical reasons at the expense of the amount of alcohol add small amounts of water, then the dissolution slows down des / 3 polyamide. Such solutions are used expediently with a high content of calcium rhodanide. Subsequently, such Solutions with alcohol can be diluted again to the claimed 20 to 28 percent by weight.

Possible alcohols are: ethyl alcohol or butyl alcohol, but especially methyl

609 660/394

alcohol, which is particularly suitable for the production of the spinning solutions.

According to the method of the invention, spinning solutions can be prepared from pV polylactams, e.g. B. of / S-methyl-jö-butyrolactam,, pVdimethyl-ß-butyrolactam,,, jff-trimethyl-jS-butyrolactam, / S-carbomethoxy- / S-butyrolactam or their copolymers. ¹

For example

Suspended in a kneader to 425 g poly / S-methyl-jS-butyrolactäm (relative viscosity 14.3, dissolved in 1 ° / _o ig concentrated sulfuric acid) in 1388 grams of methyl alcohol and contributes to this mixture, 1020 g of Calciumrhodanid with 4,15_Mol Water of crystallization, corresponding to 690 g of anhydrous calcium rhodanide. During the introduction of salt, the polymer quickly dissolves in the cold. The mixture is then stirred for a further 5 to 8 hours and filtered in a pressure filter through a filter layer of cotton wool and batiste and then a filter layer of cotton wool and 1 mm thick cotton paper cardboard. The ball drop of the 15% polyamide solution is 450 seconds at 25 ° C. (steel ball 0 3 mm). The highly viscous solution is carefully diluted with methyl alcohol to 13% polyamide, the ball drop is 40 seconds after the dilution and increases in the case of the 13% solution, slowly increased from 40 to 53 seconds after 90 hours. At a dilution of 12.5 ° / ₀ Poly-pMactam the ball case is only 24 seconds, but this solution is coagulated after 66 hours.

Example 2

In a kneader is mixed '294 g poly / S-methyl- | 5-butyrolactam (relative viscosity 10.6 ⁰ J ₀ dissolved in concentrated sulfuric acid l ° / _o solution) with 946 g Calciumrhodanid with 4.15 mole of water of crystallization, corresponding to 648 g calcium thiocyanate anhydrous, and then allows a mixture of 1222 g methyl alcohol and 64 g water to flow in. The polymer dissolves rapidly in the cold. To be on the safe side, the mixture is stirred for another 3 to 5 hours and filtered just as intensively as described in Example 1. The filtered 15% solution fell as a ^{ball to 139 seconds at 25 °} C. (3 mm of the ball), 70 seconds after dilution to 14% poly- / S-lactam, and a ball fall of 72 seconds was measured after a standing time of 5 days . The solution is therefore practically stable in viscosity. If it is diluted to 13%, the ball fall drops to 40 seconds, and after a rapid increase in viscosity, the solution coagulates after 5 days.

Example 3

34.1 g of poly - /? - methyl - /? - butyrolactam are mixed in a glass flask and 71.4 g calcium rhodanide with 1.95 mol of water, corresponding to 58.4 g calcium rhodanide anhydrous, and then allows 122 g of methyl alcohol to run in. After 2 hours the Solution through a pressure filter as in Example 2. The ball fall is 140 seconds after 5 days 143 seconds at 25 ° C (0 of the sphere 0.3 mm).

Claims (1)

Claim: Spinning solutions containing polyamides and rhodanides dissolved in alcoholic solutions, thereby characterized in that they are polymeric / J-methyl- / S-butyrolactams as polyamides or their copolymers, containing calcium rhodanide as rhodanide and that in the spinning solutions the weight ratio of polymer / S-methyl- / 3-butyrolactam to calcium rhodanide 1: 1.3 to 1: 1.8 and that the calcium rhodanide concentration is 20 to 28%. Considered publications:
German Auslegeschrift No. 1107 399;
Patent No. 1776 of the Office for Inventions and Patents in the Soviet zone of occupation in Germany. 609 660/394 9.66 © Bundesdruckerei Berlin